Political scientists have long been concerned about the effects of vot
er-registration rules on election-day turnout, but have devoted little
effort to explaining interstate differences in voting procedures. Wha
t leads one state to adopt permissive registration laws and another to
enact restrictive laws? In addition, what is the precise relationship
between registration laws and measures of popular participation? This
article takes a first step toward answering these questions, utilizin
g Daniel J. Elazar's concept of political culture and causal-modeling
techniques. The results indicate that political culture offers a signi
ficant, theory-driven explanation for differences in voter-registratio
n laws and voter turnout among the American states.